1. Field of the Invention
The present invention relates to a remote control transmitter used mainly for operating various electronic equipment and a transmitting-receiving system using the remote control transmitter.
2. Background Art
Recently, remote controlling of various equipment such as video, audio and air conditioning equipment has been widely carried out by using a remote control transmitter. In particular, in a game machine, or the like, a plurality of persons often operate one equipment by using their respective remote control transmitters. Therefore, remote control transmitters with little operational misjudgment or malfunction have been demanded.
Such a conventional remote control transmitter and a transmitting-receiving system using the same are described with reference to FIGS. 6 to 9. FIG. 6 is an overall view showing a conventional transmitting-receiving system. Remote control transmitter 1 shown in FIG. 6 has the following configuration. Remote control transmitter 1 includes substantially box-shaped case 1A made of an insulating resin; a plurality of operation keys 1B protruding on the upper surface of case 1A; switch contacts (not shown) provided in case 1A, which allow electrical connection and disconnection by the operation of operation keys 1B; and built-in controlling means 1C such as a microcomputer and a light emitting diode for transmitting a remote control signal corresponding to the operation. Receiver 5 shown in FIG. 6 includes, in the front surface thereof, display section 5S such as a liquid crystal display device and receiving section 5D such as a microcomputer. A transmitting-receiving system is configured by receiver 5, remote control transmitter 1, and a plurality of remote control transmitters 2 and 3 formed in the same manner as in remote control transmitter 1.
In the above-mentioned configuration, the first case of an operation example is described. In the first case, for example, a plurality of persons play a game such as a quiz game. When a question of the quiz is displayed on display section 5S of receiver 5, a person having remote control transmitter 1 presses operation key 1B for answering the question, control means 1C detects this and transmits an infrared ray remote control signal to receiver 5. Signal waveform 7A in FIG. 7 shows a change over time of a transmit signal waveform. In signal waveform 7A in FIG. 7, transmission codes V1 are arranged in a predetermined period X1.
As shown in a waveform diagram of a transmission code shown in FIG. 8A, transmission code V1 of the remote control signal includes, in detail, header data VA shown in FIG. 8B, operation key data VB of “0010” being unique to the pressed operation key and including a combination of “0” in FIG. 8C and “1” in FIG. 8D, remote control identification data VC1 of “0001” for identifying individual remote control transmitters, and stop bit data VD shown in FIG. 8E.
At this time, when another person having remote control transmitter 2 presses an operation key for answering the question slightly later, the remote control signal is transmitted as shown in signal waveform 7B in FIG. 7. The remote control signal is transmitted from remote control transmitter 2 to receiver 5. The remote control signal has transmission codes V2 arranged in period X2 that is larger than period X1. At this time, in transmission code V2, header data VA, operation key data VB and stop bit data VD are the same as those of transmission code V1. Only the remote control identification data are different from remote control identification data VC1 of remote control transmitter 1.
Receiver 5 receives two remote control signals from remote control transmitters 1 and 2. Since the first transmission code V1 of signal waveform 7A and the first transmission code V2 of signal waveform 7B are received almost simultaneously and data are superimposed on each other, receiver 5 cannot decode them. Then, however, when the receiver receives the second transmission code V1 of signal waveform 7A in FIG. 7 from remote control transmitter 1 after period X1 and thereafter receives the second transmission code V2 of signal waveform 7B in FIG. 7 from remote control transmitter 2 after period X2, the receiver receives individual transmission codes separately because there is a difference between period X1 and period X2. Therefore, receiver 5 can decode a remote controller that transmitted each signal. Then, receiver 5 judges that remote control transmitter 1 is operated earlier than remote control transmitter 2 because it decodes a signal from remote control transmitter 1 firstly. Then, for example, in a game, a point is given to a person having remote control transmitter 1.
Then, the second case of an operation example is described. FIG. 9 shows a change over time of a signal waveform when remote control transmitter 2 is operated slightly earlier than remote control transmitter 1. When signal waveform 9A of remote control transmitter 1 and signal waveform 9B of remote control transmitter 2 are compared with each other, first transmit codes V1 and V2 of remote control transmitters 1 and 2 are superimposed on each other. Therefore, receiver 5 cannot decode them. However, second transmission codes V1 and V2 are not superimposed on each other. Therefore, receiver 5 can decode them. Then, receiver 5 makes a comparison on the orders of transmission operation of both signals. Also at this time, receiver 5 judges that remote control transmitter 1 is operated earlier than remote control transmitter 2 because receiver 5 decodes a signal from remote control transmitter 1 firstly. That is to say, a conventional transmitting-receiving system makes misjudgment and malfunction, that is, it judges that remote control transmitter 2 is operated later although remote control transmitter 2 is operated slightly earlier.
An example of prior art information related to the invention of this application includes Japanese Patent Application Unexamined Publication No. 10-98787. As described in the above, a remote control transmitter and a transmitting-receiving system according to a conventional technology tend to cause misjudgment or malfunction when a plurality of remote control transmitters are operated simultaneously or operated with a slight time difference.